[mapserver-users] How to dynamically change MapServer's GRID MININTERVAL?

[David Miller]

I started looking into using something similar to this example of the GRID
layer definition in a MapServer mapfile that will draw lat/lon line grid at
least every 5 degrees:

LAYER
  NAME "grid"
  METADATA
    "DESCRIPTION" "Grid"
  END
  TYPE LINE
  STATUS ON
  CLASS
    NAME "Graticule"
    COLOR 0 0 0
    LABEL
      COLOR  255 0 0
      FONT "sans"
      TYPE truetype
      SIZE 8
      POSITION AUTO
      PARTIALS FALSE
      BUFFER 2
      OUTLINECOLOR 255 255 255
    END
  END
  PROJECTION
    "init=epsg:4326"
  END
  GRID
    LABELFORMAT '%g°'
    MININTERVAL 5
  END
END # Layer

However, I don't want the MININTERVAL value to be hardcoded and would like
to be able to vary that value by entering a different value in the URL call
from a web page using the map_object notation. But, I've been unsuccessful.
I have tried this in the URL call to MapServer:

&map_layer[grid].grid[0]=MININTERVAL+10 #changing to 10 degrees instead of 5

using the second example at this link:
https://mapserver.org/cgi/controls.html#cgi-mapfile-change-parameters. But,
I either get a parsing error or an Internal Server error. I've tried
turning debug level to 5 and looking at logs but they don't offer any help.
Perhaps I'm just not using the correct map_object notation, but I'm not
sure what else to use given the examples in the link. I also attempted to
look at the MapServer code to no avail.

Perhaps I just can't change this parameter via the URL?

I'm using MapServer v 7.2.2 but it seems like the GRID layer has been
available for a while now.

Thanks for any help/suggestions/thoughts!

Dave M
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